Search

The pulsed laser ablation technique is a safe and eco-friendly method, this technique was used to prepare gold (Au) and zinc oxide (ZnO) in two forms, both as core:shell nanoparticles (CS NPs) and a nanocomposite (NC). The absorption behaviour for Au/ZnO NCs and Au:ZnO CS NPs was investigated the UV-visible of Au NPs peak at 525 nm whiles the peak of the ZnO NPs at 375 nm. Transmission electron microscope (TEM) images show the average size of Au NPs is 30–45 nm adhering to ZnO NPs with an average size of 55–60 nm. In Au/ZnO CSNPs, Au acts as a core while the ZnO nanoparticles produced a shell; in spherical gold nanoparticles, the average shell thickness of ZnO is 10–15 nm. As synthesised, the Au:ZnO CSNPs are endowed with high photocatalytic activity even after multiple cycles of photo-catalytic reactions when compared with Au/ZnO NCs. [ABSTRACT FROM AUTHOR]

Nanoparticles of gold with zinc oxide (Au@ZnO NPs) were prepared by laser ablation and then capped with curcumin nanoparticles (Cur-Au@ZnO NPs). The synthesized NPs were characterized using different techniques, including transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), UV-visible spectroscopy, and X-ray diffraction. In addition, the ability of NPs as a promising antibacterial agent was tested against Staphylococcus aureus through the agar well diffusion method and AO/EtBr staining assay. The results showed that the prepared nanoparticles (Cur-Au@ZnO) served as an antibacterial agent and can destroy the bacterial cells by losing the cell wall integrity and penetrating the cytoplasmic membrane. Moreover, the findings confirmed the role of the formed NPs in attenuation of the adherence and invasion of S. aureus to rat embryonic fibroblast (REF) cells. Furthermore, the activity of Cur-Au@ZnO NPs against the S. aureus α-hemolysin toxin was evaluated using the western blot technique, using human alveolar epithelial cells (A549), and through histopathology examination in a mouse model. In conclusion, the built Cur-Au@ZnO NPs can be used as a potential antibacterial agent and an inhibitor of α-hemolysin toxin secreted by S. aureus. These NPs may offer a new strategy in combating pathogen infections and in the future for biomedical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Early detection of nitrogen oxide gases has become a vital process even at low concentrations. Herein, iron oxide nanoparticles)IO NPs( were prepared by hydrothermal technique (homemade reactor) followed by doping with copper and gold (Cu/Au NPs) via laser ablation, and they were used for NO2 gas sensing. The microstructures of IO NPs before and after the doping were characterized by UV-Vis spectrum UV-visible spectroscopy, field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). The results have shown a change in the shape, whereas the particle size has grown post the doping by 30%. The optical energy gap of pure IO NPs is approximately 3.0 eV, and the Cu/Au IO NPs are reduced to 2.75 eV. The Cu/Au IO NPs have excellent behaviour as gas sensing properties towards nitrogen dioxide (NO2) gas in the operating temperature range of RT 200 °C. Relative to IO NPs, Cu/Au IO NPs exhibited the best response of 85 towards NO2 at RT. This response is over two times as high as compared with IO NPs. The enhanced NO2 sensing mechanism of the IO NPs could be attributed to the synergistic effects of catalytic activity and chemical sensitization by doping of Cu/Au NPs. [ABSTRACT FROM AUTHOR]

In this study, prepared Au:ZnO core-shell nanoparticles (CSNPs) by pulse laser ablation in liquid (PLAL), and succeed to control of growth the ZnO NPs and play a role as a shell decorated on surface of Au NPs as a core. The structure, morphology and visual qualities were examined. The XRD result explained the phase of ZnO NPs was wurtzite structure, and for Au NPs as a cubic crystal. The morphology of structures illuminates the agglomerated and adherent ZnO NPs on Au NPs. TEM image is clearly show the spherical particles for Au NPs with mean size 12 ± 1 nm, and the mean size for ZnO NPs is 29 ± 2 nm, while, its clearly show increased for size of Au:ZnO CSNPs to 45 ± 2 nm. [ABSTRACT FROM AUTHOR]

In this study, synthesis and characterizing of Gold:Zinc Oxide (Au:ZnO) as a core:shell nanoparticles (CSNPs) has been prepared via Laser Ablation at various Laser Pulses Energy 400, 600, and 800 mJ with 200 strokes. Further confirmation of the production of Au:ZnO CSNPs by analyzing the structural and optical properties from aggregated Au:ZnO. CSNPs obtained via drop casting Au:ZnO CSNPs colloidal solutions into silicon wafers. Nanoparticles were identified via X-ray diffraction, transmission electron microscopy, Fourier transform infrared, and ultraviolet–visible absorption spectrum. It was found particle size increased with energy, and the shell of ZnO on the surface of gold nanoparticles is strongly affected on absorptions, while the absorption of Au:ZnO CSNPs decreased when the decorated surface of Au by ZnO corresponding to Au and ZnO as an individual. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (Ag NPs) dispersed in deionized water (DW) are prepared using the Nd:YAG laser ablation method. Transmission electron microscopy (TEM) results were used to investigate the shape and particle size of Ag NPs. The spherical shape and size of about 30 nm are characterized. X-ray diffraction (XRD) analysis shows a good crystallinity of Ag NPs and distinguished peaks at 38° without any impurities. The optical properties of Ag NPs were studied by a UV–visible spectrophotometer, and the surface plasmon resonance was observed at an excitation wavelength of about 402 nm and a direct band gap of about 2.25 eV. The results of the inhibitory activity against Lactobacillus and Streptococcus mutans bacteria indicated areas of high inhibition. The highest inhibition zone was 19 mm at the stock concentration. The anticancer properties of Ag NPs were studied with multi-concentration; the small particle size of Ag NPs led to the killing of about 70% of the MCF-7 line; and the inhibitory concentration (IC50) of Ag NPs was about 93.55 µg/mL−1. [ABSTRACT FROM AUTHOR]

A zinc oxide–silver doped with graphite and nitrogen (ZnO/Ag doped with C/N) heterostructure was prepared by a simple method with a study of the photodegradation of methylene blue (MB) dye under sunlight irradiation. Results from X-ray diffraction (XRD) experiments show the presence of sharp peaks for ZnO, Ag, and C, with the wurtzite phase of ZnO. Energy-dispersive X-ray spectroscopy (EDX) results match the results of XRD and confirm the presence of Ag, Zn, C, O, and N. Field emission scanning electron microscope (FESEM) images confirm the presence of clusters of spherical nanoparticles (NPs). The optical properties results confirm the high-absorption ability in the visible area with an energy gap of 2.95 eV. After 140 min of exposure to sunlight radiation, the photocatalysis results show that the MB dye can be broken down very well by light. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles (IONPs) were synthesized by combining garlic and onion peel extracts with iron (III) chloride salt (FeCl 3) in a simple chemical method to develop an environmentally green treatment for toxic dyes. Onion and garlic peels act as reducing, stabilizing, and anti-caking agents to rapidly transform FeCl 3 salt into IONPs. A change in the color of the resulting solutions indicates the formation of IONPs. X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), UV–visible (UV–vis), and Fourier-transform infrared (FTIR) spectroscopy were used to characterize the structural and optical properties of IONPs. The FeO NPs were constructed using a garlic peel extract. They were 34–70 nm in size with a cubic structure, while the Fe 2 O 3 NPs synthesized using an onion peel extract were 37–66 nm in size with a hexagonal structure. FE-SEM images showed the biosynthesized FeO NPs had a nanosheet-like structure with a particle size of 24–44 nm, and biosynthesized Fe 2 O 3 NPs demonstrated a nanofiber-like structure with a particle size of 29–32 nm. UV–vis measurements indicated a blue shift for the energy gap value from 3.1 eV for biosynthesized FeO NPs to 4.1 eV for biosynthesized Fe 2 O 3 NPs. The strong FT-IR absorption peaks at 650 and 660 cm−1represented an Fe–O vibration band for the biosynthesized FeO and Fe 2 O 3 NPs, respectively. Methylene blue (MB) degradation was rapid using biosynthesized Fe 2 O 3 and FeO NPs, reaching 97% at 30 min and 90% at 35 min. These degradation rates indicate the effectiveness of the application of IONPs in the removal of MB dye through the adsorbent process. Green synthesis of iron oxide nanoparticles (IONPs) were prepared by combining (garlic and onion) peels extract with iron chloride (III) salt (feCl 3) through a simple chemical method at 200 °C for 2 h. The main objective of this research is the environment treatment of toxic dyes. The (onion and garlic) peels acts as a reducing, stabilizing, and anti-caking agent to transform FeCl 3 salt to IONPs in a short period of time. It is observed that a change in the color of the resulting solutions indicates the formation of IONPs. By using different physical techniques such as X-ray Diffraction (XRD), Field Emission-Scanning Electron Microscopy (FE-SEM), UV–Visible (UV–Vis), Fourier Transform Infrared (FT-IR), the structural and optical properties of IONPs were characterized. The crystallite size of FeO NPs using the garlic peel extract ranged from (34–70) nm with a cubic structure, while the crystallite size increased from (37–66) nm for Fe 2 O 3 NPs synthesized using the onion peel extract with a hexagonal structure. FE-SEM images showed a nanosheet-like structure with a particle size of (24–44) nm for FeO NPs synthesized using the garlic peel extract. The morphology of Fe 2 O 3 NPs synthesized using the onion peel extract revealed a nanofiber-like structure with a smaller particle size of (29–32) nm. UV–vis measurements indicated a blue shift for the energy gap value from 3.1 eV for FeO NPs using the garlic peel extract to 4.1 eV for Fe 2 O 3 NPs using the onion peel extract. The peak of strong absorption at 650 and 660 cm−1 indicated that an Fe–O vibration band reported on the FT-IR spectrum belongs to FeO and Fe 2 O 3 NPs using the garlic and onion peel extract, respectively. This experiment indicates successful removal of methylene blue (MB) by application of IONPs through the adsorbent process. The results of quick degradation efficiency of MB dye by Fe 2 O 3 NPs prepared using the onion peel extract reached 97% at 30 min, with high photocatalytic activity than that observed with FeO NPs prepared using the garlic peelextract, for which the degradation efficiency was 90% at 35 min. • First, the synthesis bioactive materials of eco-friendly IONPs (FeO and Fe2O3) by a simple chemical method using new plant peels extract. • Secondly, the first time (garlic and onion) peels were used to prepared bioactive, and safe materials of IONPs. • Third, bioactive materials of IONPs were used in environmental treatment for remove the toxic blue methylene dye under room normal light irradiation. • Finally, Because of the effectiveness of IONPs have demonstrated their ability to quick remove dyes without catalysts and other external factors in very short time because have high active. [ABSTRACT FROM AUTHOR]